Consumer Reports magazine warned car buyers to avoid the 2010 Lexus GX 460 sport utility vehicle because of a handling problem that could lead to a rollover and possibly “serious injury or death.”

A “don’t buy” warning is rare for the magazine, but there was no doubt it was necessary, said David Champion, senior director of its auto test division. The litmus test was whether the testers would want their families in the vehicle. The answer was no, he said, so “I wouldn’t want anybody else in it.”

The handling problem arises if the driver of a Lexus GX 460 SUV lifts off the gas pedal while driving quickly through a sharp turn. That causes the rear end of the vehicle to slide toward the outside of the turn, a condition known as “trailing throttle” or “lift-throttle oversteer.”

On dozens of other SUVs tested by the magazine, the electronic stability control system of the vehicles detected and quickly stopped the slide. But the stability control did not stop the GX 460 until it was almost sideways, Champion said.

A spokeswoman for Lexus, Toyota’s luxury car division, said the company was “puzzled” by the magazine’s results because it conducts its own tests, and safety is a top priority. She added that Lexus “will take a very serious look at this and appreciates Consumer Reports bringing it to our attention.”

The magazine’s action is another public relations problem for Toyota. In addition to complaints about unintended acceleration and Prius brakes, there have been questions over whether the automaker was prompt in reporting problems to federal safety investigators.

Most recently the federal government said it was seeking a $16.4 million fine, accusing the automaker of not acting quickly enough.

Champion said that the SUV problem came to light at the magazine’s test track in East Haddam, Conn., while looking for “any nasty habits that might catch a driver out.” He said,

The particular test that concerned the magazine involves a turn that suddenly gets sharper. The driver enters at about 60 mph and then, as if surprised, lifts off the gas. Ideally, the electronic stability control would stop a slide caused by that maneuver, allowing the vehicle to safely complete the turn.

Champion said such a problem could happen in everyday driving. For example, a driver heading quickly through a turn — like a highway off-ramp — who finds the turn is sharper than expected would naturally lift off the gas, he said.

In a statement, Lexus complained that the magazine had not demonstrated the problem for its representatives. Champion said, however, that on the day the officials visited the track, it rained, making a precise duplication impossible. Lexus officials were shown a video of their earlier tests.